4-06CW229 Supplemental Data

• Case Number: 06CW0229
• Stream Name: South Fork Smith Fork Gunnison river
• Watershed: Upper Gunnison
• Water Division: 4
• Water District: 40
• County: Gunnison
• Instream Flow App - Doc Type: Supplemental Data

Bioloizic Flow RecoMxpendation
The summer flow recommendation, which met 3 of 3 criteria and is within the accuracy range of
the R2CROSS model is 6.4 cfs (See Table 1). The winter flow recommendation, which met 2 of
3 criteria and is within the accuracy range of the R2CROSS model range is 4.1 cfs (See Table 1).
Hydrologic Data
After receiving the cooperating agency's biologic recommendation, the CWCB staff conducted
an evaluation of the stream hydrology to determine if water was physically available for an
instream flow appropriation. The hydrograph below was derived from data collected by the
USGS stream gage for Smith Fork Gunnison River near Crawford, CO (ID #09128500), which
has a drainage area of 42.8 square miles (See Gage Summary in Appendix Q. The total
drainage area of this segment of the South Fork of the Smith Fork Gunnison River is
approximately 15.9 square miles. The period of record for this gage was 1935 to 1994, the
period of record used by staff in their analysis was 1935 - 1994, or 60 years of record. Table 2
below displays the estimated flow of South Fork Smith Fork Gunnison River at the gage, in
terms of a percentage of exceedence.
Table 2: Estimated Stream Flow in South Fork Smith Fork Gunnison River
Exceedences
jan
feb
mar
apr
may
jun
jul
aug
sep
Oct
nov
Dec
1%
7.0
8.1
26.9
113.4
255.7
198.7
48.7
12.6
12.2
13.3
10.4
7.4
5%
4.8
5.2
15.5
84.5
158.5
127.5
26.3
8.7
8.5
10.0
7.0
5.2
10%
3.5
4.1
11.8
66.2
132.8
101.8
21.1
7.0
7.0
7.4
5.6
4.1
20%
3.0
3.5
7.0
44.4
107.7
65.1
15.2
5.6
5.2
5.6
4.4
3.4
50%
2.4
2.6
4.1
21.5
61.4
32.9
8.1
3.7
3.1
3.2
3.0
2.6
80%
1.9
2.0
2.8
8.9
34.0
18.5
4.8
2.7
2.1
2.4
2.4
2.0
90%
1.8
1.9
2.4
5.9
26.6
13.0
3.6
2.1
1.8
2.1
2.1
1.9
95%
1.7
1.7
2.1
5.0
19.6
9.6
2.8
1.6
1.4
1.9
2.0
1.8
99%
1.4
1.6
1.9
3.3
8.4
6.2
2.0
1.0
1.1
1.5
1.7
1.4
Estimated Stream Flow on South Fork Smith Fork
20.0
15.0
10.0
5.0
0.0
Month
-4-
jan feb mar apr may jun jul aug sep oct nov dec